A radiation detector on a laboratory bench is switched on when there are no radioactive samples in the laboratory. The count rate displayed by the detector is 24 counts per…

An electric fan heater contains a heating element and a motor that drives the fan. The circuitdiagram is shown.At first, the switch is open and the current in the motor…

A measuring cylinder resting on an electronic balance contains a liquid as shown in diagram 1. A small solid object X is gently lowered into the liquid and no liquid…

A wave travelling through a material has a frequency of 50 Hz and a wavelength of 0.40 m. How long does it take the wave to travel 100 m through…

A puddle is left on a road after a rain shower. The water in the puddle slowly disappears by evaporation. Three statements about the effect of changing different conditions on…

Nickel has an atomic number of 28. The mass numbers of four of its isotopes are 58, 60, 61and 62.Below are three statements about these isotopes of nickel.1 All of…

A 100% efficient step-down transformer decreases the voltage of an alternating current (a.c.) electricity supply. What effect does this step-down transformer have on the mean power transferred and the alternating…